Influence of multiple environmental factors on the quality and flavor of watermelon juice.

Ye Liu,Xiao Yang,Congcong He,Huanlu Song

doi:10.1039/c9ra01533g

Abstract

Environmental factors (heat, pH, oxygen, light) can induce significant quality changes in watermelon juice during processing. To ascertain the effect of such factors on the quality of watermelon juice, the total soluble solids (TSSs), turbidity, lycopene content, color, and flavor were evaluated during different treatments. The pH had a slight impact on the content of lycopene, but had an obvious impact on turbidity. Heat, oxygen, and illumination had considerable effects on the color of watermelon juice, and the results were visible. The content of aldehydes [hexanal, nonanal, (E)-2-noneal, (Z)-6-nonenal] and ketones (6-methyl-5-hepten-2-one, geranylacetone, β-ionone) decreased in treated watermelon juices, while those of 1-nonanol, (Z)-3-nonen-1-ol and (E,Z)-3,6-nonadien-ol increased during illumination. The order of influence of environmental factors on watermelon-juice quality was light > pH > oxygen > heat.

Highlights

Watermelon juice is becoming increasingly popular due to its refreshing taste, attractive color/ avor and potential health bene ts.[1,2] Watermelon contains health-promoting phytochemicals such as lycopene, b-carotene, avonoids, phenolic compounds and vitamins.[3,4] Phytochemicals are known to have antioxidant effects, which can protect against diabetes mellitus, cancer, hypercholesterolemia, and various other oxidative stress-induced chronic diseases.[5,6]watermelon is a heat-sensitive fruit, the quality and avor of which is affected by environmental factors
The color variations observed in watermelon juice were attributed to a decrease in lycopene content (25%), as well as reductions in residual peroxidase activity (16.8%) 10 days a er hyperbaric storage at 100 MPa.[14]
No signi cant differences were observed in total soluble solids (TSSs) a er thermal treatments (p > 0.05)

Summary

Introduction

Watermelon juice is becoming increasingly popular due to its refreshing taste, attractive color/ avor and potential health bene ts.[1,2] Watermelon contains health-promoting phytochemicals such as lycopene, b-carotene, avonoids, phenolic compounds and vitamins.[3,4] Phytochemicals are known to have antioxidant effects, which can protect against diabetes mellitus, cancer, hypercholesterolemia, and various other oxidative stress-induced chronic diseases.[5,6]watermelon is a heat-sensitive fruit, the quality and avor of which is affected by environmental factors. Com; Tel: +86-010-68984547 the L* value increased from 43.2 to 45.8 a er 2 days of storage at 4 C, and removing rinds accelerated senescence.[10] In addition, pasteurization at 87.7 C for 20 s and storage for up to 30 days at 4 or 8 C has been shown to signi cantly reduce the red color and levels of bioactive compounds (lycopene, antioxidant capacity and total polyphenols) of watermelon juice, if the storage time is extended and a temperature of 8 C was used.[11] ultrahigh-temperature treatment (120 and 135 C) has been shown to inactivate microbial colonies and maintain the original color of watermelon juice, and to maintain the phenolic content by reducing polyphenol oxidase activity.[12] Ultrahigh-temperature (135 C for 2 s) and lowtemperature long-term treatment (60 C for 30 min) can reduce the total ora count and maintain the color of pasteurized watermelon juice, whereas the high-temperature, shortterm treatment can lead to a signi cant color difference.[13] The color variations observed in watermelon juice were attributed to a decrease in lycopene content (25%), as well as reductions in residual peroxidase activity (16.8%) 10 days a er hyperbaric storage at 100 MPa.[14]

Methods

Results

Conclusion